mongoc_stream_read()#

Synopsis#

ssize_t
mongoc_stream_read (mongoc_stream_t *stream,
                    void *buf,
                    size_t count,
                    size_t min_bytes,
                    int32_t timeout_msec);

Parameters#

stream: A mongoc_stream_t.
buf: The buffer to read into.
count: The number of bytes to read.
min_bytes: The minimum number of bytes to read, or else indicate failure.
timeout_msec: The number of milliseconds to wait before failure, a timeout of 0 will not block. If negative, use the default timeout.

The mongoc_stream_read() function shall perform a read from a mongoc_stream_t. It’s modeled on the API and semantics of read(), though the parameters map only loosely.

Warning

The “default timeout” indicated by a negative value is both unspecified and unrelated to the documented default values for *TimeoutMS URI options. To specify a default timeout value for a *TimeoutMS URI option, use the MONGOC_DEFAULT_* constants defined in mongoc-client.h.

Returns#

The mongoc_stream_read() function returns the number of bytes read on success. It returns >= 0 and < min_bytes when end-of-file is encountered and -1 on failure. errno is set upon failure.